Research About the Spurious Trip Rate of Digital RPS Based on FMEA

摘要

Digital control system (DCS) is the central nervous system of automation monitoring and controlling of nuclear power plant. Safe operation and economic benefits of nuclear reactor units depend heavily on the performance of DCS. DCS consists of hardware and control logic. Mai-Operation Rate and Anti-Operation Rate are two important measures to evaluate the reliability of DCS. Failure Mode and Effects Analysis (FMEA) is now in common use to analyze the failures of hardware and control logic. FMEA has been widely used in assessing DCS of nuclear power plant. Fault Tree Analysis (FTA) is effective in analyzing causes and effects of failures. Based on the top-down analyzing strategy, it can easily identify the basic reason accident. Reactor protection system (RPS) is the most important part of DCS, which is used to guarantee the reactor stay in a safety state. This paper takes Spurious Trip Rate of RPS as example, analyzing how different failure modes affect reliability of RPS based on the method of FMEA and FTA. This method can also apply to analyze engineered safety features actuation system (ESFAS), and even the whole DCS of nuclear power plant, which can provide guidance for the design, operation and maintenance of nuclear power plant.